This invention relates generally to microelectronic processing and in particular to filling one or more spaces on the surface of a substrate.
Plasma assisted deposition of films is widely used in microelectronics manufacturing. For example, dielectric films are often deposited in gaps or trenches on a substrate surface for use in isolation, passivation and barrier applications. However, completely filling a gap with the deposited material may prove to be challenging. This is especially true for those gaps having a high depth to width ratio. For example, typical deposition plasmas tend to deposit a non-uniform film in the gap that results in excess deposition at or near the opening of the gap as compared to the bottom of the gap. As a result, a void may form in the gap.
Generally, voids are undesirable because the electrical or physical isolation to be provided by the gap is disrupted. Thus, if present, voids may cause degradation in the performance of or even the failure of the circuit in which they occur.
Therefore, there is a continuing need for microelectronic processing techniques to deposit films that fill gaps on the surface of a substrate.